The Nutrient-Nut is 5'9" but walks around like he's 6'0"
One of the great advantages to being shorter is that it's so much easier to fill the frame out and look huge!
I know that 5'8" use to be the average height for Bodybuilders, but I don't know if that's changed. It does seem like people are getting taller and taller compared to what the norm was 10-20 years ago.